Reciprocating floor conveyor for conveying palletized loads or the like

Abstract

A reciprocating floor conveyor (10) including a support frame (12), and a conveyor floor (14), which is comprised of a plurality of laterally spaced-apart conveyor slats (16), a plurality of laterally spaced-apart holding slats (18), and a series of divider planks (20). Divider planks (20) are fixedly secured to the upper portion of support framework (12). Conveyor slats (16) are mounted on support frame (12) for longitudinal reciprocation between "start" and "advanced" positions. Holding slats (18) are mounted on support frame (12) for vertical movement between and "up" position in which the holding slats (18) are above the conveyor slats (16), and a "down" position, in which the holding slats (18) are below the conveyor slats (16). The load is conveyed by lowering the holding slats (18), advancing the conveyor slats (16), to convey the load, raising the holding slats and retracting the conveyor slats to their "start" position, and repeating the process.

What is claimed is: 
     
       1. A reciprocating floor conveyor for conveying articles having fixed-form wide bases, comprising: a support frame;   a plurality of laterally spaced-apart conveyor slats mounted on the support frame for longitudinal reciprocation between a start position and an advanced position, the conveyor slats having upper surface portions with a constant vertical height that defines a horizontal conveying plane;   a plurality of laterally spaced-apart holding slats mounted on the frame for vertical movement between an up position in which the upper surfaces of the holding slats are above the conveying plane defined by the conveyor slats and the articles are supported by the holding slats, and a down position in which the upper surfaces of the holding slats are below the conveying plane and the articles are supported by the conveyor slats; each holding slat including a top, two laterally spaced sides extending downwardly from the top, and two bottom flanges, one extending laterally from a bottom portion of each side;   the conveyor slats and the holding slats being distributed across the conveyor in a pattern resulting in both conveyor slats and holding slats being below each article on the conveyor;   a holding slat base for each holding slat, each holding slat base having opposite laterally extending flanges positioned between the bottom flanges and the top of the corresponding holding slat to limit vertical movement of the holding slat; wherein a collapsible pocket is formed vertically between the holding slat and its base; and   an expandable member located in each collapsible pocket, wherein expansion of the expandable members raises the holding slats from their down position to their up position to lift any articles on the conveyor up off the conveyor slats to permit the conveyor slats to be retracted from their advanced position to their start position while the conveyor slats are out of contact with the articles.   
     
     
       2. The reciprocating floor conveyor of claim 1, wherein the conveyor slats are mounted on the support frame for longitudinal reciprocation in a manner so that the movement of the conveyor slats is restricted to longitudinal reciprocation. 
     
     
       3. The reciprocating floor conveyor of claim 1, wherein the movement of the holding slats is restricted to vertical movement. 
     
     
       4. A reciprocating floor conveyor for conveying articles having fixed-form wide bases, comprising; a support frame;   a plurality of laterally spaced-apart conveyor slats mounted on the support frame for longitudinal reciprocation between "start" and "advanced" positions;   a plurality of laterally spaced-apart holding slats mounted on the frame for vertical movement between an "up" position in which the holding slats are above the conveyor slats, and a "down" position in which the articles are supported by the conveyor slats;   the conveyor slats and the holding slats being distributed across the conveyor in a pattern resulting in both conveyor slats and holding slats being below each article on the conveyor;   means for moving the conveyor slats and any article on them from the "start" position to the "advanced" position, when the holding slats are in their "down" position, for conveying the articles, and for retracting the conveyor slats, when the holding slats are in their "up" position and are holding the articles up off the conveyor slats; and   a holding slat base for each holding slat and an expandable member between each holding slat and its holding slat base, wherein expansion of the expandable members moves the holding slats from their "down" position to their "up" position;   wherein between each holding slat and its holding slat base is formed a collapsible pocket in which the expandable member is located;   wherein each collapsible pocket is formed by an upper surface of the holding slat base and the under surface of the holding slat, with the under surface extending above the upper surface of the holding slat base and downwardly past the edges of the upper surface; and   wherein each holding slat base includes a flat upper surface with lateral flanges extending transversely to the holding slat base, and each holding slat includes a top, two sides extending downwardly from the lateral edges of the top, and two bottom flanges, one extending inwardly from the bottom edge of each side, the lateral flanges of the holding slat bases being situated between the top and bottom flanges of the holding slats.   
     
     
       5. The reciprocating floor conveyor of claim 4, and further comprising additional expandable members located between the lateral flanges of each holding slat base and the bottom flanges of each holding slat, one additional expandable member located on each side of each holding slat base, whereby expansion of the additional expandable members causes the holding slats to move from their "up" position to their "down" position. 
     
     
       6. The reciprocating floor conveyor of claim 1, further comprising a transverse drive beam coupled to each conveyor slat and a drive unit for reciprocating the transverse drive beam. 
     
     
       7. The reciprocating floor conveyor of claim 6, wherein the drive unit includes a hydraulic actuator motor. 
     
     
       8. The reciprocating floor conveyor of claim 7, wherein the hydraulic actuator motor includes a pair of fixed, spaced-apart piston/piston rod units and a movable cylinder unit mounted for reciprocating movement on the pistons, the transverse drive beam being mounted to the cylinder unit. 
     
     
       9. The reciprocating floor conveyor of claim 1, and further comprising a plurality of divider planks interspersed on the support frame between some of the conveyor slats. 
     
     
       10. The reciprocating floor conveyor of claim 1, further comprising a first control arm extending downwardly from one of the holding slats and a second control arm adjacent the first control arm, one of said control arms including a pair of spaced abutments positioned to contact the other control arm, the first control arm being adapted to shift the second control arm between a first position and a second position as the holding slat moves between its up and down positions. 
     
     
       11. The reciprocating floor conveyor of claim 10, further comprising a control system for controlling operation of the reciprocating floor conveyor, the control system including a valve coupled to the second control arm, the control system adapted to reverse movement of the conveyor slats in response to movement of the second control arm. 
     
     
       12. The reciprocating floor conveyor of claim 1, wherein the holding slat base includes a recessed longitudinal channel, and the expandable member is positioned, at least partially, within the longitudinal channel. 
     
     
       13. The reciprocating floor conveyor of claim 1, wherein the holding slat base includes a U-shaped channel beam with outwardly-extending rails, and the holding slat includes a main portion and a bearing for supporting the main portion, the bearing including a pair of pockets in which the outwardly-extending rails are received for up and down movement. 
     
     
       14. The reciprocating floor conveyor of claim 13, wherein the expandable member is positioned within the U-shaped channel beam and under the bearing. 
     
     
       15. The reciprocating floor conveyor of claim 1, wherein the holding slat base includes a U-shaped channel beam with outwardly-extending upper flanges, and the holding slat includes a main portion and a bearing having a central portion adapted to slide up and down within the U-shaped channel beam, the bearing adapted to support the main portion of the holding slat, the expandable member being positioned between the central portion of the bearing and the U-shaped channel beam. 
     
     
       16. The reciprocating floor conveyor of claim 1, wherein the holding slat includes a downwardly-extending central portion and the holding slat base includes a U-shaped channel beam into which the central portion of the holding slat extends, the expandable member being positioned between the central portion of the holding slat and the U-shaped channel beam. 
     
     
       17. The reciprocating floor conveyor of claim 1, wherein the holding slat includes a downwardly-depending central wall intermediate the laterally spaced sides, the central wall including a head, and wherein the holding slat base includes a box beam, and the central wall extends into the box beam, the box beam having outer shoulders adapted to engage the bottom flanges of the holding slat and limit upward movement of the holding slat. 
     
     
       18. An apparatus (of claim 28,) for raising and lowering an article supported thereon, comprising: a base having an upper surface and opposite laterally extending flanges;   a slat member carried on the base and having a top, two laterally spaced sides depending downwardly from the top, and two bottom flanges, one extending laterally from a bottom portion of each side, the flanges of the base being positioned between the bottom flanges and the top of the slat member to limit vertical movement of the slat member, wherein a collapsible pocket is formed vertically between the slat member and the base;   an expandable lift member sandwiched between the base and the slat member in the collapsible pocket; whereby, with article supported on the slat member, expansion of the lift member moves the top of the slat member away from the base, thereby raising the article, and contraction of the lift member allows the top to move toward the base, thereby lowering the article; and   a pair of expandable lowering members, each located between a bottom flange of the slat member and a laterally extending flange of the base, whereby expansion of the pair of expandable lowering members and contraction of the lift member causes the slat member to move toward the base, and contraction of the expandable lowering members and expansion of the lift member causes the slat member to move away from the base.   
     
     
       19. The conveyor of claim 1, in which the sides of the holding slat provide lateral support for the expandable member. 
     
     
       20. The conveyor of claim 1, in which the bottom flanges of the holding slat extend laterally inwardly toward each other, and the flanges on the holding slat base extend outwardly in opposite lateral directions.